Discrete paving elements (“herein pavers”), such as bricks, stones and tiles are commonly used for outdoor patios, parking lots, cobble stone streets, and similar paved structures. The pavers are usually supported on a substrate layer comprising one or more layers of aggregate or other materials to provide a level surface for the pavers when installed.
Strength of the paver structural system is a design consideration when implementing the system. The paver structural system is subjected to compression loading from both static loading of objects on top of the paved surface and from live loading of pedestrian or vehicular traffic moving across the paved surface. The paver structural system should be strong enough to withstand the anticipated loading.
Reducing surface runoff from paved surfaces is another design consideration. When the paved surfaces receive rain or other fluids, drainage ideally occurs downward through the paver structural system.
Further, the paver structural system is subjected to environmental wear and tear that can impair the ability to drain the fluids, such the deposit of sand, grit, dirt, motor oil, organic soils and roots, dust, debris, etc. onto the paved surface.
Additionally, cement binders are not preferable uses for permeable joint material. Large aggregate sizes are required in permeable mixtures that use cement binders, which are too large for use as a joint material, do not readily flow into small spaces, are easily clogged by debris, and will stain surrounding materials.
Thus the resulting paver structural system, including the joints between the pavers, should be strong enough to withstand the compression loading and be permeable enough to allow for the drainage of fluids, even when subjected to wear and tear. As a result, there is a need for an improved structural system of pavers having a permeable joint that provides compression strength and permeability, as well as protection of the sublayer from clogging debris.